Scaffold hoist



Patented Jan. 16, 1923.

UNITED stares raam carica.

Manifs ABEL M. KNECHTEL, 0F DETROIT, MICHIGAN.

scArFoLn Hors'r. i

Application led November 9, 1921.-v Seral No. 513,943.

It is an object of the invention to provide a scaffold adjustingmechanism operable by a workman upon the scaffold platform and requiringrelatively small manual effort.

A further object is to provide an anchorage means for securing the topof a scaffolding to a building, which anchorage means may be veryquickly operable from the foot of the scaffolding. j

In attaining these and various other objects, the invention contemplatesproviding a pair of uprights, each carry-ing a special formvof rack, anda platform extending be tween said uprights and guided by the same in avertical travel effected by manually rotating pinions meshing with saidracks. Said objects are further achieved by providing slides upon theupper ends of said uprights carrying spikes engageable with a cornice ofthe building to anchor the upper end of the scaffolding, said slidesbeing controlled by ropes passing over suitable pulleys and thenceextending to the ground.

A preferred embodiment of the invention is hereinafter described, and isillustrated in the accompanying drawings, wherein,

Fig. 1 is an end view of the improved scaold showing also a portion of abuilding to which the upper end of the scaffold is anchored. V

Fig. 2 is a side view of thesame.

Fig. 3 is an enlarged view of a portion of Fig. 1, showing primarily thespecial type.

of rack and pinion and cranks for actuating the latter. y

Fig. 4 is a vertical sectional view of the saine, the section beingtaken on l-ine 4 4 of Fig. 3.

Fig. 5 is a cross-section view of one of the anchorage slides which aremounted at the top of the scaffolding, the section being taken on line 55 of Fig. 2.

In these views the reference character 1 designates a pair of uprights,which are preferably madeV hollow to minimize the weight thereof.v Saiduprights are formed in sections of convenient length, and a suitablenumber of these sections may be joinedv to obtain the desired height.vA-preferred means for'joining the sections isa filler block f 2extending equally into the abuttingf .end

)ortions as is seen in Fi014. The nner l a e portions of the uprights 1are respectively embraced byslides, each comprising a pair of plates 3,and hollow bolts 4 connecting said plates, said bolts having rollers 5mounted thereupon to bear upon the uprights. Within each bolt 4, a rod 6is ad# justably secured by a set screw 7,* corresponding ends of saidrods being uptur'ned to carry a connecting bar 8.` In the ends of thebars 8 there are engaged'screws 9vhaving upwardly proj ecting pointedends which are adapted to embed themselves in the cornice 10 of thebuilding 11 when' said slide is moved abruptly upward. Fachof saidslides is actuable verticallyl by a rope-'152 which is extended to thelower portion Yof the corresponding upright after being carried over apulley 13 -journaled inthe up*- right above said slide. The lowerends oflthe ropes 12 may be secured in anyfsuitable manner, as for example, byattachment. to

pins 14 driven into the' uprights. It is preferred to'subject the ropesto springtension, '1

' this being accomplished in a simple manner byextending a coiled spring15 across 'a slack portion of each rope. Bythus tensioning the ropes,any settlingof the uprights 11 that may occur dur-ing use thereof yisprevented from loweringthe anchorage members 9 out of proper engagementwith the cornice 10.

- Between the uprights 1 there is extended 'a scaffold platformcomp-risingspacedplanks 16 and a pair of cleats 17.v Said planks projectat their ends beyond said cleatsand embrace the uprights 1, ywhicharethus' adapted to guide the platform in its vertical travel.v rIo the'ends of each cleat 17 there isv secured a pair of upwardlyextending'convergent straps 1,8, the upper,I end portions ofwhich areparallel and embrace a post 19, one end of which is centrally secured toeachl cleat 17. Said straps projectfsuiiciently above type, the teeththereof being hemispherical. As shown, said pinions are formed integralwith said shafts. To the opposed faces of the uprights, there arerespectively secured vertically elongated metal plates 23 each formedwith two rows of staggered perforations 24 forv engagement by thepinions 21. The perforations 2d of each row register transversely withthe centersbetween perforations of the adjacent row, and the teeth ofthe two pinions 21 are correspondingly relatively staggered. Thisengagement has the advantage that one or more teeth of each pair ofpinions 21 are always engaged with the corresponding plate 23. Theplates 23 may be formed in sections preferably co-extensive with thesections of the uprights 1, the ends of said plate sections beinginturned as indicated at 25 to enga-ge end faces of the uprightsections. It is preferred to form channels 26 in the opposed faces ofthe uprights, registering respectively with the rows of perforations 24,and accommodating the end portions of the pinion teeth projectingthrough said perforations. 27 are crank arms mounted respectively uponthe ends of each shaft 20, adapting the same to be rotated by a workmanupon the scaffold. 28 is a brake wheel which is fast upon each shaft andis engageable b-y a brake shoe 29 manually controlled by an integra-llever 30 to regulate rotation of the pinions 21 when the platform isbeing lowered. For holding the platform in any desired position ofvertical adjustment there are provided two dogs 31, respectivelylocated' within recesses 32 in the posts, said dogs being pivoted attheir upper ends and each having upon its lower portion a pair of teeth33 for engaging adjacent perforations 24. Said dogs are each urgedtoward the adjacent perforated plate 23 by a coiled spring 34, and areeach furthermore provided with a pivotal latch handle 35 passing looselythrough a plate 36 secured to theinner face of the corresponding post19. By first pulling out upon the latch handle and then depressing saidhandle to the position shown in dash lines in Fig. 4, a notch 37 of saidlatch handle may be engaged with an edge of the plate 36 to hold the dogdisengaged from the corresponding plate 23.

Considering now the operation of the described invention, the first stepin erecting the scaolding is to assemble the sections' forming each ofthe hollow uprights 1. This may be very quickly accomplished, since itis necessary only to insert the yfiller blocks 2 in the abutting endportions of the sections. The scaffold 16 is now disposed in itsposition of use adjacent the buildingll and the uprights: 1 are placedon end, passing respectively through the ends of the platform.

The upper ends of the scalfold are now anchored to the building by meansof the slides 3. Said slides are first lowered, by means of the ropes12, some distance below the eaves of the building. By suddenly jerkingupon the ropes the slides are now raised with considerable force so asto firmly embed the sharp spikes 9 into the cornice. Thus the upper endsof the uprights are securely anchored. After anchoring the lowerext-remities of the uprights by any suitable mea-ns, the platform 16 maybe adjusted to any desired elevation by turning the cranks 27. The dogs31 will offer no resistance to raising of the platform, o-wing to theupper edges of the teeth of said dogs being beveled. Said dogs, however,will act automatically to maintain the platform in any position of use.ln lowering the platform, a brake control lever 30 may be grasped by onehand of a workman while with theother hand the latch handle 35 is movedto its release position, shown in dashlines in Fig. 4. By regulating thebraking pressure the platform may be lowered at such speed as may bestsuit the operator. It will be evident that the described scaffold may beoperated to best advantage by two men positioned respectively at eachend of the platform.

The primary advantages secured by the invention are a very considerablesaving of time both in erecting and taking down a scaffold, and theelimination of block and tackle control means, requiring considerabletime to install and subject to a much greater danger of accidents thanthe described apparatus.

What I claim is:

1. In a device of the character described, the combination with ascaffolding upright, of a slidable member freely movable longitudinallyof said upright, a pulley mounted in the upright above said slidablemember, a-fleXible member secured to the slidable member passing overthe pulley and extending to the lower portion of the upright, and ananchorage member carried by the slidable member and engageable with abuilding through raising of the slidable member by said flexible member.

2. ln a device of the character described, the combination with ascaffolding upright, of a slidable member embracing the upright, movablelongitudinally thereof, a laterally projecting rod carried by saidslidable member, an upwardly projecting anchorage member at one end ofsaid rod, and means for raising said slidable member from the lowerportion of the scaffold. j

In testimony whereof l sign this specification.

.ABEL M. KNECHTEL'.

